Experience in performing the Cernavoda spent fuel interim storage facility

Full text: At the level of 1980-1989 years, the Cernavoda site was designed and licensed to be erected 5 CANDU 600 Mw Units. Until now, only first unit was put in operation in December 1996 and Unit 2 will be commissioned in the first part of 2006 years. The others units there are erected and completed at different levels. The Romanian Government declared itself favorable for analyzing the possibility to continue the nuclear program with completion of Units from Cernavoda site. The yearly arising of the design spent fuel quantity in operation of one CANDU 600 MW unit, is about 94 tones Uranium natural (approx. 4800 CANDU bundles). Each units, includes a Spent Fuel Storage Bay which has a storage capacity for spent fuel produced in approximate 9 years. Taking in view the increased number of spent fuel bundles obtained in operation the load factor obtained till now was and is still better like the design load factor) and the limited free space from the existing Spent Fuel Bay, at the level of 2000 years, Nuclearelectrica SA, as owner of Cernavoda NPP, issued a Tendering Document for an International Bidding Process. The Tendering process was based on the results of support studies, including a feasibility study performed in advance under Romanian Research and Development Programs, some years ago. Also, an important support was obtained under the IAEA Technical and Research Programs. The result, it was selected a dry solution and taking in view the schedule for commissioning the N.P.P Units 3 / 5 is uncertain, for distributing the investments according to the real storage requirements, a modular concept was proposed, placed on the boundary of plant site. The winner of the bidding process was AECL Company from CANADA for an offer which has as reference Point Lepreau solution for preparing of the spent fuel for dry storage and Gentilly 2 solution for dry storage facility. In April 2001, a Contract was signed between SNN and AECL for this facility which will use CANSTOR type concrete monolithic modules, already are in operation in Gentilly 2 CANADA, since 1995. The facility has a storage capacity for the spent fuel obtained from 30 years in operation of the Unit 1 and 2. The deadline for commissioning of this facility is May 2003. Local Romanian companies, SITON for engineering and licensing documentation work and Nuclearmontaj for construction and procurement work were involved in this project(percentage more than 85%) as AECL subcontractors. During the performing of this facility was gained an important experience, in different fields, more important being engineering work, construction work, procurement activity and in special licensing process. The licensing process was a good experience from our point of view and has some particular aspects compare with other similar facility process. These could be specified as following: 1. Support documentation for Licensing process fulfilled the US - NRC Regulatory Guide 3.48 'Standard content for the safety analysis report' and US - NRC 10 CFR part 72 'Licensing requirements for an independent storage spent fuel and high level radioactive waste' requirements (although Cernavoda SFIDSF is located inside the boundary of NPP site). 2. Evaluation of an aircraft crash on the CANSTOR module consequences was included into the safety analysis. The results were considered in the emergency plan. 3. Radiological effects on operators and public were evaluated taking into account the multiple contributions of all radiation sources, existing in Cernavoda site NPP. The paper intends to present an overview on this facility and the experience gained by Romania during the construction of this objective inside the Cernavoda NPP plant. (author)